The proposed research is an investigation of the mechanisms of conformational transformations or proteins, nucleic acids, and phospholipid model membranes. The experimental approach is based on the recognition that these processes proceed through a multitude of intermediate states closely spaced in free energy. A mechanistic understanding of the transformations requires the experimental detection and characterization of these intermediate states. Kinetic studies appear to provide the most sensitive approach to these problems. It is important to measure the kinetics of response to the smallest possible perturbations consistent with precise measurements. This should elicit a response which reflects the properties of the least possible number of intermediate states. Hence use of minimal perturbations should make possible a more detailed demonstration of the overall complexity of the mechanism of the transformation and should yield data which is simplest to interpret in terms of the elementary components of the entire process. An apparatus using small pressure perturbations to study conformational dynamics has been constructed and proved in several types of applications. Optical and conductometric methods are used to monitor the progress of the conformational transitions. The apparatus and methods will be further simplified and improved and will be applied to study the following phenomena: 1) folding of proteins; 2) the gel- liquid crystal transformation in phospholipid bilayer vesicles; 3) the helix-random coil transition in natural DNA.